How to Prime an Infusion Pump: What a Smiths Medical Order Taught Me

The day I realized I didn't know how to prime an infusion pump

On a Tuesday morning last March, I stood in the ICU supply room holding a Smiths Medical Medfusion syringe pump in one hand and a cold cup of coffee in the other. The pump screen said 'SELECT SYRINGE SIZE' and then 'PURGE?' I had approved the purchase of fourteen of these pumps two months earlier. I had never primed one myself.

I am a supply chain coordinator at a 170-bed community hospital. I have been ordering medical equipment for twelve years. That sentence makes me sound experienced. It also means I know exactly how much damage a confident purchase order can do.

In my first year, I ordered an electric wheelchair for a patient whose doorway measured twenty-eight inches. The wheelchair was thirty inches wide. We found out when the delivery team tried to push it into the patient's room. It did not fit. The patient waited another week, the vendor charged a $450 restocking fee, and I learned that 'will this physically fit in the building?' is a legitimate procurement question.

A few years later, I almost ordered a biosafety cabinet without confirming whether the lab needed Type A2 or Type B2. The lab director asked me, 'What is your exhaust plan?' I had no answer. We paused the order. I learned that biosafety cabinets are not interchangeable, and that NSF/ANSI 49 certification matters. So I was not a beginner when it came to medical equipment mistakes. But infusion pumps humbled me in a way I did not expect.

Our standing order for Smiths Medical tracheostomy tubes was the part of the supply list I felt good about. We used Portex tubes in the ICU and step-down units. I knew the difference between cuffed and uncuffed. I knew to check for inner cannulas. That confidence, it turned out, was exactly the problem.

The infusion pump replacement project started in February 2024. The hospital received a grant to upgrade our older pumps. We evaluated four options. I chose Smiths Medical Medfusion pumps for two reasons: the device profile fit our ICU workflow, and the local support contact was responsive. The boxes arrived with a sticker that listed Smiths Medical Keene NH as the support location. I put that sticker in our vendor file and moved on.

We scheduled a thirty-minute nurse demo before go-live. It got pushed twice because of staffing needs. I was not worried. Pumps have been around for decades. Priming can't be that complicated. I said that sentence out loud to our biomedical engineer. He said, 'Can you do it right now?' I could not.

How to prime an infusion pump: the steps I now use

The first time I tried to prime one, I was alone. I connected a filled syringe to an extension set, loaded the syringe into the pump, and pressed the menu button. The pump asked for the syringe size. I selected 60 cc. It asked 'PURGE?' I pressed yes. I watched the line for ten seconds. Nothing moved. The pump started beeping. I did not know why.

The reason was embarrassing: the extension set clamp was closed. The pump was trying to push fluid through a closed path. That is not a pump malfunction. That is a user training gap.

I called the number on the box. The call routed to the Smiths Medical Keene NH support team. The technician asked three questions: What syringe size? What extension set? Is the clamp open? The last one stopped me. She explained the priming sequence calmly, and did not make me feel stupid (which, honestly, I appreciated).

Here is the sequence that now sits above our pump storage area. Please read the manual that came with your pump, because the screen language varies by model. But for a syringe pump, the general steps are:

1. Draw the medication or fluid into a syringe and remove large air bubbles by tapping the barrel and pushing the plunger slightly.
2. Attach the extension set to the luer-lock tip. Keep the clamp closed for now.
3. Load the syringe into the pump. Confirm the syringe size and volume on the screen.
4. Open the clamp before you start the prime function. This is the step I skipped. If the clamp is closed, the pump can alarm during priming.
5. Select the prime or purge option, and watch the line until fluid reaches the end of the tubing without air bubbles.
6. Stop the prime, close the clamp, and leave the system capped if you are not connecting it to a patient right away.

Oh, and the extension set matters as much as the syringe. A short line with a small internal volume primes faster than a long line with a large dead volume. That changes how long you hold the syringe and how much medication you need to waste.

At least, that is how our lead ICU nurse explained it to me after she watched me try it. The official manual was clear too. The first time I read it properly, I found a note that said: prime the extension set with the clamp open. I had skipped that page.

What that mistake changed

At first, I considered rolling out the pumps without extra training. The upside was saving a week of nursing time. The risk was staff using a device they did not understand. I kept asking myself: is saving one week worth potentially causing an air-in-line alarm in the middle of an IV infusion? The answer, eventually, was no.

We did not stop buying Smiths Medical products. We stopped buying them without a plan for hands-on education. When I later built the checklist for a Smiths Medical tracheostomy tube order, I had to learn why flange style matters and why packaging integrity cannot be skipped. For biosafety cabinets, the checklist now includes NSF/ANSI 49 testing status and exhaust configuration. For an electric wheelchair, the first line is: measure the doorways before you submit the order.

I don't have hard data on how many priming errors happen across hospitals. But based on the alarms our biomed team reviewed over the next three months, I would guess that loading and priming mistakes caused a meaningful share of the nuisance alarms on our new pumps. That was a system problem, not a pump problem.

In the past eighteen months, our inventory audit log shows forty-seven potential errors caught using these checklists. That number is not impressive in a national sense. It matters to the patients and nurses who did not have to deal with those errors.

This approach worked for us because we are a single ICU with a standard protocol. If you are a home infusion agency or a multi-site health system, your checklist will be different. Your mileage may vary. The important part is to spend hands-on time before rollout, not after.

I now start every product introduction with a simple sentence: I would rather spend ten minutes explaining how a device works than deal with mismatched expectations later. An informed customer asks better questions and makes faster decisions. The Smiths Medical Keene NH support team did not sell me the pump twice. They just answered the phone and helped me understand it. That is what good customer education looks like.

If you are reading this because you just ordered new infusion pumps, do yourself a favor. Open one, watch the official video, or call the support line before the go-live date. Or better yet, ask the trainer to watch you prime a pump while you explain what you are doing. I wish I had.